An object with a mass of 5kg is hanging from an axle with a radius of 12cm. If the wheel attached to the axle has a radius of 38cm, how much work would it take to turn the wheel a length equal to the circumference of the axle?

1 Answer
Apr 23, 2016

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As shown in the figure
The radius of the Wheel R=38cm
The radius of the Axle r=12cm
The mass of the object m=5kg
The Weightof the object W=mg=5×9.8N
P is the applied force.
The Displacement of Applied force(P)=Circumference of the axle =d=2×π×12cm=24π×102m
The working principle of wheel -axle system may be compared with the working principle of First Kind of lever

So
P×R=W×rP=W×rR=5×9.8×1238N

Hence the Work done =P×d=5×9.8×1238×24π×102J=11.7J